ReadingTimeMachine/rtm-sgt-ocr-v1 · Datasets at Hugging Face

source stringlengths 1 2.05k ⌀	target stringlengths 1 11.7k
Other work on radiative transfer modeling of the torus in AGN has been preseuted by Pier RKrolik (1992). Cranato Danese (199D). Nenkova et al. (	Other work on radiative transfer modeling of the torus in AGN has been presented by Pier Krolik (1992), Granato Danese (1994), Nenkova et al. (
2002. Ww108). Dulleniond. vau Bemunel (2005). Tommie et al. (	2002, 2008), Dullemond van Bemmel (2005), Hönnig et al. (
2006) aud ποιαπα et al. (	2006) and Schartmann et al. (
2008).	2008).
Tn this paper we use radiative transter models of starburst. cirrus auc ACN torus cussion to constralu the properties of SAICs with spectroscopic redshifts aud mud-intrared spectroscopy and far-infrared photometry Sect.	In this paper we use radiative transfer models of starburst, cirrus and AGN torus emission to constrain the properties of SMGs with spectroscopic redshifts and mid-infrared spectroscopy and far-infrared photometry (Sect.
2) fromSpifzer.	2) from.
For comparison two cdiffereut starburst models are applied: auceolutionarg model (Efstathiou et al.	For comparison two different starburst models are applied: an model (Efstathiou et al.
2000) that lucorporates a stellar population svuthesis imeocdel and therefore provides information about the stellar population that powers the starburst (Sect.	2000) that incorporates a stellar population synthesis model and therefore provides information about the stellar population that powers the starburst (Sect.
1) aud aspot model (Siebeninoreen Irüssel 2007) that is sensitive to the ecometry of the dust aud stars and therefore provides information about the size of the starburst region (Sect.	4) and a model (Siebenmorgen Krüggel 2007) that is sensitive to the geometry of the dust and stars and therefore provides information about the size of the starburst region (Sect.
5).	5).
A flat Universe is asstuned with A=0.73 aud Hy2 71m/s/Mpc.	A flat Universe is assumed with $\Lambda = 0.73$ and $_0=71$ km/s/Mpc.
Our suuple is determined solely by the requirement that the ealaxics have been detected in the subimillimeter and have nüddunfrared spectroscopy frou, the infrared spectrograph (IRS. Houck et al.	Our sample is determined solely by the requirement that the galaxies have been detected in the submillimeter and have mid-infrared spectroscopy from the infrared spectrograph (IRS, Houck et al.
2001) of the Spitzer Space Telescope (SST. Werner et al.	2004) of the Spitzer Space Telescope (SST, Werner et al.
2001).	2004).
We model all the ealaxies in the PAID sample of \Lenéddez-Deluestre et al. (	We model all the galaxies in the PAH sample of Menéddez-Delmestre et al. (
2006). except SAIAT J221733\|001120 which is at low redshift aud which is clearly dominated by cimus emission. and the objects in the sample of Valiaute et al. (	2006), except SMM J221733+001120 which is at low redshift and which is clearly dominated by cirrus emission, and the objects in the sample of Valiante et al. (
2007).	2007).
The data in the sample of Moenéddez-Deliuestre. οἳ al.	The data in the sample of Menéddez-Delmestre et al.
COVOL he silicate feature and therefore provide information about the extinction iu the galaxies but the objects iu the sample of Valiaute et al.	cover the silicate feature and therefore provide information about the extinction in the galaxies but the objects in the sample of Valiante et al.,
beime at higher redshift. do not cover completely the silicate band.	being at higher redshift, do not cover completely the silicate band.
Iu total there are 12 objects spanuniug a redshift range from 1.2 to 2.1 (Table 1).	In total there are 12 objects spanning a redshift range from 1.2 to 3.4 (Table 1).
Besides IRS. ISOCAAL (Webb et al.	Besides IRS, ISOCAM (Webb et al.
2003) aud submillimeter photometry (Simail et al..	2003) and submillimeter photometry (Smail et al.,
2002. Scott ot al.	2002, Scott et al.,
2006. Ivison et al.	2006, Ivison et al.
2005. Zemcov ct al.	2005, Zemcov et al.
2007) we complement the SED by retrieving all publicly available data of the Spitzer far infrared nuager (APS. Ricke et al.	2007) we complement the SED by retrieving all publicly available data of the Spitzer far infrared imager (MIPS, Rieke et al.
2001) of the targets in the three photometric chauncls centered at 21. 70 aud 16052. AIIPS raw data are processed by the Spitzer pipeline (version S16.1: Cordon et al.	2004) of the targets in the three photometric channels centered at 24, 70 and $\mu$ m. MIPS raw data are processed by the Spitzer pipeline (version S16.1; Gordon et al.
2005) to a flux calibrated mosaic nuage.	2005) to a flux calibrated mosaic image.
The various mosaic nuages of a particular target aud chaunel aud from the different. programs aud observers are combined to a final image wingSWARP?.	The various mosaic images of a particular target and channel and from the different programs and observers are combined to a final image using.
. For the τὸ aud 160/242 bands we use the filtered mosaic nuages of the pipeline (see MIPS Data Taudboolk).	For the 70 and $\mu$ m bands we use the filtered mosaic images of the pipeline (see MIPS Data Handbook).
The final nuage has higher redundancy aud signaltonoise than the one obtained from data of a particular observiug sequence.	The final image has higher redundancy and signal–to–noise than the one obtained from data of a particular observing sequence.
Iu the 21420 band all sources are detected and final nuüages are shown iu Fie. l..	In the $\mu$ m band all sources are detected and final images are shown in Fig. \ref{i24.ps}.
Iu this baud SAGs appear well separated from other sources.	In this band SMGs appear well separated from other sources.
Iu the other channels. at 70 and 160422. with the exception of SAMAL J02399-0136. SALCs remain undetected.	In the other channels, at 70 and $\mu$ m, with the exception of SMM J02399-0136, SMGs remain undetected.
The fiux is derived using an aperture centered on the first Airy ving aud a 2 pixel wide background aunulus outside the second Airy vine: colour aud PSF correction factors are applied.	The flux is derived using an aperture centered on the first Airy ring and a 2 pixel wide background annulus outside the second Airy ring; colour and PSF correction factors are applied.
The photometric error is better than	The photometric error is better than.
MIPS photometry of the SMCis is eiven in Table 1 aud agree with IRS.	MIPS photometry of the SMGs is given in Table \ref{obs.tab} and agree with IRS.
We verified our procedure on the calibration standard star ITD106252.	We verified our procedure on the calibration standard star HD106252.
For this star all MIPS {μαι data are pipeline processed and mosaic Ónnauages coadded with SWARP toa final nage.	For this star all MIPS $\mu$ m data are pipeline processed and mosaic images coadded with SWARP to a final image.
Ou this image we measure a flux which is consistent to within with the flux measured by Eneelbracht et al. (	On this image we measure a flux which is consistent to within with the flux measured by Engelbracht et al. (
2007) on the same star.	2007) on the same star.
We first compare the data of the galaxies i our sample with pure cirrus aud pure starburst models.	We first compare the data of the galaxies in our sample with pure cirrus and pure starburst models.
For the cirrus chussion we follow au approach simular to that of ERRO: except that we do uo attempt to link the opticalUV chussion with the infrared in a selfcousisteut mame.	For the cirrus emission we follow an approach similar to that of ERR03 except that we do not attempt to link the optical-UV emission with the infrared in a self-consistent manner.
We first determine the ucar-intrared to UV spectrum by assundue an age for he ealaxy and a star formation history.	We first determine the near-infrared to UV spectrum by assuming an age for the galaxy and a star formation history.
We use the stellar population svuthesis model of Druzual Charlot (1993) with a Salpeter IAIF aud stellar iuasses iu the range AL...	We use the stellar population synthesis model of Bruzual Charlot (1993) with a Salpeter IMF and stellar masses in the range $\ M_\odot$.
For this study we assumnie. as m ERROS. an age of 250Ma8 and a star formation rate that is constant with time.	For this study we assume, as in ERR03, an age of 250Myrs and a star formation rate that is constant with time.
For the last 5MSYS we asstune that the stars are οοσα imu the molecular clouds in which they formed so they do not	For the last 5Myrs we assume that the stars are embedded in the molecular clouds in which they formed so they do not
Cigahertz Peaked Spectrum (GPS. c.g. O'Dea 1998) are à class of cxtragalactic radio source. characterised by a convex shaped radio spectrum peaking at about 1 CLlz in frequency. ancl sub-galactic sizes.	Gigahertz Peaked Spectrum (GPS, e.g. O'Dea 1998) are a class of extragalactic radio source, characterised by a convex shaped radio spectrum peaking at about 1 GHz in frequency, and sub-galactic sizes.
Pheir small sizes make observations using Verv Long Baseline Interferometry (VLBI) necessary to reveal their radio morphologies.	Their small sizes make observations using Very Long Baseline Interferometry (VLBI) necessary to reveal their radio morphologies.
Early VLBI observations showed that some GPS sources identified with galaxies have Compact. Double (CD) morphologies (Philips and Mutel. 1982). and it was suggested. that these were the mini-lobes of very voung or alternatively old. frustrated. objects (Philips and Mutel. 1982: Wilkinson et al.	Early VLBI observations showed that some GPS sources identified with galaxies have Compact Double (CD) morphologies (Philips and Mutel, 1982), and it was suggested that these were the mini-lobes of very young or alternatively old, frustrated objects (Philips and Mutel, 1982; Wilkinson et al.
1984. van Breugel. Miley and Leckman. 1984).	1984, van Breugel, Miley and Heckman, 1984).
Later. when reliable VLBI observations at higher frequencies became possible. it was found that some of the CD-sources had. a compact Hat spectrum component in their centres (Conway ct al.	Later, when reliable VLBI observations at higher frequencies became possible, it was found that some of the CD-sources had a compact flat spectrum component in their centres (Conway et al.
1992. Wilkinson et al.	1992, Wilkinson et al.
1994).	1994).
Phese Dat spectrum components were interpreted as the central cores. and many C'D-sources were renamed Compact triples or Compact. Symmetric Objects (CSO. Conway ct al.	These flat spectrum components were interpreted as the central cores, and many CD-sources were renamed compact triples or Compact Symmetric Objects (CSO, Conway et al.
190005. Wilkinson et al.	1992, Wilkinson et al.
1994).	1994).
High dynamic range VLBI observations by Dallacasa et al (1995) and Stanghellini et al. (	High dynamic range VLBI observations by Dallacasa et al (1995) and Stanghellini et al. (
1997) have shown that most GPS ealaxies indeed have jets leading from the central compact core to the outer hotspots or lobes.	1997) have shown that most GPS galaxies indeed have jets leading from the central compact core to the outer hotspots or lobes.
This is in contrast to the GPS sources identified with quasars. which tend to have core-jel morphologies with no outer lobes (Stanghellini οἱ al.	This is in contrast to the GPS sources identified with quasars, which tend to have core-jet morphologies with no outer lobes (Stanghellini et al.
1997).	1997).
Snellen et al. (	Snellen et al. (
1999) have shown that the recshift distributions of the GPS galaxies and quasars are very cdilferent. and that it is therefore unlikely that they form a single class of object unified by orientation.	1999) have shown that the redshift distributions of the GPS galaxies and quasars are very different, and that it is therefore unlikely that they form a single class of object unified by orientation.
They suggest that they are separate classes of object. which just happen to have the same racdio-spectral morphologies.	They suggest that they are separate classes of object, which just happen to have the same radio-spectral morphologies.
The separation velocities of the hotspots have now been measured for a small number of GPS galaxies to be Q.2h te COwsianik and Conway. 1998: Owsianik. Conway and Polatidis. 1998: Vschager ct al.	The separation velocities of the hotspots have now been measured for a small number of GPS galaxies to be $0.2h^{-1}$ c (Owsianik and Conway, 1998; Owsianik, Conway and Polatidis, 1998; Tschager et al.
1999).	1999).
This makes it very likely that these are voung objects of ages tvpically M0) vr (assuming a constant separation velocity). rather than old objects constrained in their growth by a dense ESAL.	This makes it very likely that these are young objects of ages typically $\sim 10^3$ yr (assuming a constant separation velocity), rather than old objects constrained in their growth by a dense ISM.
These are therefore the objects of choice to study the carly evolution of extragalactie radio sources.	These are therefore the objects of choice to study the early evolution of extragalactic radio sources.
In the past. work has been concentrated. on samples of the radio brightest GPS sources (eg.	In the past, work has been concentrated on samples of the radio brightest GPS sources (eg.
O'Dea ct al 1991).	O'Dea et al 1991).
In order to disentangle radio power and redshift effects on he properties of GPS sources. we constructed a sample of aint GPS sources [rom the Westerbork Northern Sky Survey (WENSS. Reneclink et al.	In order to disentangle radio power and redshift effects on the properties of GPS sources, we constructed a sample of faint GPS sources from the Westerbork Northern Sky Survey (WENSS, Rengelink et al.
1997). which in combination with other samples allows. for the first time. the study of these objects over a large range ofLux density and radio spectra oak frequeney.	1997), which in combination with other samples allows, for the first time, the study of these objects over a large range of flux density and radio spectral peak frequency.
The construction of the faint saniple is described in Snellen et al. (	The construction of the faint sample is described in Snellen et al. (
199823): the optical and near-infrared. imaging is described in Snellen ct al. (	1998a); the optical and near-infrared imaging is described in Snellen et al. (
1998b): anc he optical spectroscopy in Suellen et al. (	1998b); and the optical spectroscopy in Snellen et al. (
19992).	1999a).
This paper describes multi-frequency VLBI observations of the sample. and the radio-morphologies of the individual sources.	This paper describes multi-frequency VLBI observations of the sample, and the radio-morphologies of the individual sources.
Wha	What
the expected Hw luminosity even if T<10 Myrs.	the expected ${H\alpha}$ luminosity even if $<10$ Myrs.
From the figure we also see that stochasticity implies a large spread 1 the He luminosities for Levy<10 ss.	From the figure we also see that stochasticity implies a large spread in the $\alpha$ luminosities for $L_{FUV}<10^{39}$ $^{-1}$.
The presence of outliers in low-mass clusters populated according to a stochastic IMF implies that the relation betwee the cluster luminosity and its mass is no longer linear. or uniquely determined.	The presence of outliers in low-mass clusters populated according to a stochastic IMF implies that the relation between the cluster luminosity and its mass is no longer linear, or uniquely determined.
We show in Fig.	We show in Fig.
I] the distributio of cluster masses as a function of the cluster bolometric luminosity at birth.	\ref{mb} the distribution of cluster masses as a function of the cluster bolometric luminosity at birth.
We have simulated the mass distributio using for massive clusters a M — Lj, relation consister= with that given by the SED models for objects younger tha 3MMvr.	We have simulated the mass distribution using for massive clusters a $M$ – $L_{bol}$ relation consistent with that given by the SED models for objects younger than Myr.
The filled dots in the Fig.	The filled dots in the Fig.
11. are the average values of logM. in solar units. for different values of log Lj.	\ref{mb} are the average values of $log M$, in solar units, for different values of log $L_{bol}$.
For clusters. stochastic sampling of the IMF implies a mass higher. on average. than that obtained from the extrapolation of a fully populated IMF.	For clusters, stochastic sampling of the IMF implies a mass higher, on average, than that obtained from the extrapolation of a fully populated IMF.
Deviations from a linear scaling are evident as Lo; approaches 10“ ss! and become relevant for the average mass when Ly,<lO" eergss7!.	Deviations from a linear scaling are evident as $L_{bol}$ approaches $10^{40}$ $^{-1}$ and become relevant for the average mass when $L_{bol}\le 10^{39}$ $^{-1}$.
A cluster of given luminosity can be of smaller mass when some bright outlier dominates its integrated light. or can have a larger mass ifno outliers are present.	A cluster of given luminosity can be of smaller mass when some bright outlier dominates its integrated light, or can have a larger mass ifno outliers are present.
The dashed line in the Fig.	The dashed line in the Fig.
11. shows the linear approximation to the /ogM — /ogl,,; relation for clusters at birth.	\ref{mb} shows the linear approximation to the $log M$ – $log L_{bol}$ relation for clusters at birth.
We use this relation to derive the cluster mass from the fitted bolometric luminosity.	We use this relation to derive the cluster mass from the fitted bolometric luminosity.
Given a cluster age 7. we define a critical luminosity	Given a cluster age $T$ , we define a critical luminosity
Thus we may require only around 5% of the ISM to be ejected to the IGM on an average in models with f,0.2 This is comparable with semi-analytic models of early star formation. outflows and IGM enrichment that have been studied in the literature.	Thus we may require only around $5\%$ of the ISM to be ejected to the IGM on an average in models with $f_\ast \simeq 0.2$ This is comparable with semi-analytic models of early star formation, outflows and IGM enrichment that have been studied in the literature.
We have assumed the same loss fraction for ISM for galaxies over the entire range of masses.	We have assumed the same loss fraction for ISM for galaxies over the entire range of masses.
This. of course. is not true.	This, of course, is not true.
We expect that the low mass galaxies can potentially disperse a large fraction of the ISM in supernova explosions but larger galaxies can retain most of their ISM (Larson1974:Dekel&Silk1986)..	We expect that the low mass galaxies can potentially disperse a large fraction of the ISM in supernova explosions but larger galaxies can retain most of their ISM \citep{1974MNRAS.169..229L, 1986ApJ...303...39D}.
If most of the IGM enrichment is done by metals that form in dwarf galaxies then the constraint is not very stringent.	If most of the IGM enrichment is done by metals that form in dwarf galaxies then the constraint is not very stringent.
In most models. the fraction of mass in galaxies with a halo mass of less than 1027 AZ. is larger than 10X even at ><6.	In most models, the fraction of mass in galaxies with a halo mass of less than $10^{10}$ $M_\odot$ is larger than $10\%$ even at $z \simeq 6$.

Other work on radiative transfer modeling of the torus in AGN has been preseuted by Pier RKrolik (1992). Cranato Danese (199D). Nenkova et al. (

Other work on radiative transfer modeling of the torus in AGN has been presented by Pier Krolik (1992), Granato Danese (1994), Nenkova et al. (

2002. Ww108). Dulleniond. vau Bemunel (2005). Tommie et al. (

2002, 2008), Dullemond van Bemmel (2005), Hönnig et al. (

2006) aud ποιαπα et al. (

2006) and Schartmann et al. (

2008).

Tn this paper we use radiative transter models of starburst. cirrus auc ACN torus cussion to constralu the properties of SAICs with spectroscopic redshifts aud mud-intrared spectroscopy and far-infrared photometry Sect.

In this paper we use radiative transfer models of starburst, cirrus and AGN torus emission to constrain the properties of SMGs with spectroscopic redshifts and mid-infrared spectroscopy and far-infrared photometry (Sect.

2) fromSpifzer.

2) from.

For comparison two cdiffereut starburst models are applied: auceolutionarg model (Efstathiou et al.

For comparison two different starburst models are applied: an model (Efstathiou et al.

2000) that lucorporates a stellar population svuthesis imeocdel and therefore provides information about the stellar population that powers the starburst (Sect.

2000) that incorporates a stellar population synthesis model and therefore provides information about the stellar population that powers the starburst (Sect.

1) aud aspot model (Siebeninoreen Irüssel 2007) that is sensitive to the ecometry of the dust aud stars and therefore provides information about the size of the starburst region (Sect.

4) and a model (Siebenmorgen Krüggel 2007) that is sensitive to the geometry of the dust and stars and therefore provides information about the size of the starburst region (Sect.

5).

A flat Universe is asstuned with A=0.73 aud Hy2 71m/s/Mpc.

A flat Universe is assumed with $\Lambda = 0.73$ and $_0=71$ km/s/Mpc.

Our suuple is determined solely by the requirement that the ealaxics have been detected in the subimillimeter and have nüddunfrared spectroscopy frou, the infrared spectrograph (IRS. Houck et al.

Our sample is determined solely by the requirement that the galaxies have been detected in the submillimeter and have mid-infrared spectroscopy from the infrared spectrograph (IRS, Houck et al.

2001) of the Spitzer Space Telescope (SST. Werner et al.

2004) of the Spitzer Space Telescope (SST, Werner et al.

2001).

2004).

We model all the ealaxies in the PAID sample of \Lenéddez-Deluestre et al. (

We model all the galaxies in the PAH sample of Menéddez-Delmestre et al. (

2006). except SAIAT J221733|001120 which is at low redshift aud which is clearly dominated by cimus emission. and the objects in the sample of Valiaute et al. (

2006), except SMM J221733+001120 which is at low redshift and which is clearly dominated by cirrus emission, and the objects in the sample of Valiante et al. (

2007).

The data in the sample of Moenéddez-Deliuestre. οἳ al.

The data in the sample of Menéddez-Delmestre et al.

COVOL he silicate feature and therefore provide information about the extinction iu the galaxies but the objects iu the sample of Valiaute et al.

cover the silicate feature and therefore provide information about the extinction in the galaxies but the objects in the sample of Valiante et al.,

beime at higher redshift. do not cover completely the silicate band.

being at higher redshift, do not cover completely the silicate band.

Iu total there are 12 objects spanuniug a redshift range from 1.2 to 2.1 (Table 1).

In total there are 12 objects spanning a redshift range from 1.2 to 3.4 (Table 1).

Besides IRS. ISOCAAL (Webb et al.

Besides IRS, ISOCAM (Webb et al.

2003) aud submillimeter photometry (Simail et al..

2003) and submillimeter photometry (Smail et al.,

2002. Scott ot al.

2002, Scott et al.,

2006. Ivison et al.

2006, Ivison et al.

2005. Zemcov ct al.

2005, Zemcov et al.

2007) we complement the SED by retrieving all publicly available data of the Spitzer far infrared nuager (APS. Ricke et al.

2007) we complement the SED by retrieving all publicly available data of the Spitzer far infrared imager (MIPS, Rieke et al.

2001) of the targets in the three photometric chauncls centered at 21. 70 aud 16052. AIIPS raw data are processed by the Spitzer pipeline (version S16.1: Cordon et al.

2004) of the targets in the three photometric channels centered at 24, 70 and $\mu$ m. MIPS raw data are processed by the Spitzer pipeline (version S16.1; Gordon et al.

2005) to a flux calibrated mosaic nuage.

2005) to a flux calibrated mosaic image.

The various mosaic nuages of a particular target aud chaunel aud from the different. programs aud observers are combined to a final image wingSWARP?.

The various mosaic images of a particular target and channel and from the different programs and observers are combined to a final image using.

. For the τὸ aud 160/242 bands we use the filtered mosaic nuages of the pipeline (see MIPS Data Taudboolk).

For the 70 and $\mu$ m bands we use the filtered mosaic images of the pipeline (see MIPS Data Handbook).

The final nuage has higher redundancy aud signaltonoise than the one obtained from data of a particular observiug sequence.

The final image has higher redundancy and signal–to–noise than the one obtained from data of a particular observing sequence.

Iu the 21420 band all sources are detected and final nuüages are shown iu Fie. l..

In the $\mu$ m band all sources are detected and final images are shown in Fig. \ref{i24.ps}.

Iu this baud SAGs appear well separated from other sources.

In this band SMGs appear well separated from other sources.

Iu the other channels. at 70 and 160422. with the exception of SAMAL J02399-0136. SALCs remain undetected.

In the other channels, at 70 and $\mu$ m, with the exception of SMM J02399-0136, SMGs remain undetected.

The fiux is derived using an aperture centered on the first Airy ving aud a 2 pixel wide background aunulus outside the second Airy vine: colour aud PSF correction factors are applied.

The flux is derived using an aperture centered on the first Airy ring and a 2 pixel wide background annulus outside the second Airy ring; colour and PSF correction factors are applied.

The photometric error is better than

The photometric error is better than.

MIPS photometry of the SMCis is eiven in Table 1 aud agree with IRS.

MIPS photometry of the SMGs is given in Table \ref{obs.tab} and agree with IRS.

We verified our procedure on the calibration standard star ITD106252.

We verified our procedure on the calibration standard star HD106252.

For this star all MIPS {μαι data are pipeline processed and mosaic Ónnauages coadded with SWARP toa final nage.

For this star all MIPS $\mu$ m data are pipeline processed and mosaic images coadded with SWARP to a final image.

Ou this image we measure a flux which is consistent to within with the flux measured by Eneelbracht et al. (

On this image we measure a flux which is consistent to within with the flux measured by Engelbracht et al. (

2007) on the same star.

We first compare the data of the galaxies i our sample with pure cirrus aud pure starburst models.

We first compare the data of the galaxies in our sample with pure cirrus and pure starburst models.

For the cirrus chussion we follow au approach simular to that of ERRO: except that we do uo attempt to link the opticalUV chussion with the infrared in a selfcousisteut mame.

For the cirrus emission we follow an approach similar to that of ERR03 except that we do not attempt to link the optical-UV emission with the infrared in a self-consistent manner.

We first determine the ucar-intrared to UV spectrum by assundue an age for he ealaxy and a star formation history.

We first determine the near-infrared to UV spectrum by assuming an age for the galaxy and a star formation history.

We use the stellar population svuthesis model of Druzual Charlot (1993) with a Salpeter IAIF aud stellar iuasses iu the range AL...

We use the stellar population synthesis model of Bruzual Charlot (1993) with a Salpeter IMF and stellar masses in the range $\ M_\odot$.

For this study we assumnie. as m ERROS. an age of 250Ma8 and a star formation rate that is constant with time.

For this study we assume, as in ERR03, an age of 250Myrs and a star formation rate that is constant with time.

For the last 5MSYS we asstune that the stars are οοσα imu the molecular clouds in which they formed so they do not

For the last 5Myrs we assume that the stars are embedded in the molecular clouds in which they formed so they do not

Cigahertz Peaked Spectrum (GPS. c.g. O'Dea 1998) are à class of cxtragalactic radio source. characterised by a convex shaped radio spectrum peaking at about 1 CLlz in frequency. ancl sub-galactic sizes.

Gigahertz Peaked Spectrum (GPS, e.g. O'Dea 1998) are a class of extragalactic radio source, characterised by a convex shaped radio spectrum peaking at about 1 GHz in frequency, and sub-galactic sizes.

Pheir small sizes make observations using Verv Long Baseline Interferometry (VLBI) necessary to reveal their radio morphologies.

Their small sizes make observations using Very Long Baseline Interferometry (VLBI) necessary to reveal their radio morphologies.

Early VLBI observations showed that some GPS sources identified with galaxies have Compact. Double (CD) morphologies (Philips and Mutel. 1982). and it was suggested. that these were the mini-lobes of very voung or alternatively old. frustrated. objects (Philips and Mutel. 1982: Wilkinson et al.

Early VLBI observations showed that some GPS sources identified with galaxies have Compact Double (CD) morphologies (Philips and Mutel, 1982), and it was suggested that these were the mini-lobes of very young or alternatively old, frustrated objects (Philips and Mutel, 1982; Wilkinson et al.

1984. van Breugel. Miley and Leckman. 1984).

1984, van Breugel, Miley and Heckman, 1984).

Later. when reliable VLBI observations at higher frequencies became possible. it was found that some of the CD-sources had. a compact Hat spectrum component in their centres (Conway ct al.

Later, when reliable VLBI observations at higher frequencies became possible, it was found that some of the CD-sources had a compact flat spectrum component in their centres (Conway et al.

1992. Wilkinson et al.

1992, Wilkinson et al.

1994).

Phese Dat spectrum components were interpreted as the central cores. and many C'D-sources were renamed Compact triples or Compact. Symmetric Objects (CSO. Conway ct al.

These flat spectrum components were interpreted as the central cores, and many CD-sources were renamed compact triples or Compact Symmetric Objects (CSO, Conway et al.

190005. Wilkinson et al.

1992, Wilkinson et al.

1994).

High dynamic range VLBI observations by Dallacasa et al (1995) and Stanghellini et al. (

1997) have shown that most GPS ealaxies indeed have jets leading from the central compact core to the outer hotspots or lobes.

1997) have shown that most GPS galaxies indeed have jets leading from the central compact core to the outer hotspots or lobes.

This is in contrast to the GPS sources identified with quasars. which tend to have core-jel morphologies with no outer lobes (Stanghellini οἱ al.

This is in contrast to the GPS sources identified with quasars, which tend to have core-jet morphologies with no outer lobes (Stanghellini et al.

1997).

Snellen et al. (

1999) have shown that the recshift distributions of the GPS galaxies and quasars are very cdilferent. and that it is therefore unlikely that they form a single class of object unified by orientation.

1999) have shown that the redshift distributions of the GPS galaxies and quasars are very different, and that it is therefore unlikely that they form a single class of object unified by orientation.

They suggest that they are separate classes of object. which just happen to have the same racdio-spectral morphologies.

They suggest that they are separate classes of object, which just happen to have the same radio-spectral morphologies.

The separation velocities of the hotspots have now been measured for a small number of GPS galaxies to be Q.2h te COwsianik and Conway. 1998: Owsianik. Conway and Polatidis. 1998: Vschager ct al.

The separation velocities of the hotspots have now been measured for a small number of GPS galaxies to be $0.2h^{-1}$ c (Owsianik and Conway, 1998; Owsianik, Conway and Polatidis, 1998; Tschager et al.

1999).

This makes it very likely that these are voung objects of ages tvpically M0) vr (assuming a constant separation velocity). rather than old objects constrained in their growth by a dense ESAL.

This makes it very likely that these are young objects of ages typically $\sim 10^3$ yr (assuming a constant separation velocity), rather than old objects constrained in their growth by a dense ISM.

These are therefore the objects of choice to study the carly evolution of extragalactie radio sources.

These are therefore the objects of choice to study the early evolution of extragalactic radio sources.

In the past. work has been concentrated. on samples of the radio brightest GPS sources (eg.

In the past, work has been concentrated on samples of the radio brightest GPS sources (eg.

O'Dea ct al 1991).

O'Dea et al 1991).

In order to disentangle radio power and redshift effects on he properties of GPS sources. we constructed a sample of aint GPS sources [rom the Westerbork Northern Sky Survey (WENSS. Reneclink et al.

In order to disentangle radio power and redshift effects on the properties of GPS sources, we constructed a sample of faint GPS sources from the Westerbork Northern Sky Survey (WENSS, Rengelink et al.

1997). which in combination with other samples allows. for the first time. the study of these objects over a large range ofLux density and radio spectra oak frequeney.

1997), which in combination with other samples allows, for the first time, the study of these objects over a large range of flux density and radio spectral peak frequency.

The construction of the faint saniple is described in Snellen et al. (

The construction of the faint sample is described in Snellen et al. (

199823): the optical and near-infrared. imaging is described in Snellen ct al. (

1998a); the optical and near-infrared imaging is described in Snellen et al. (

1998b): anc he optical spectroscopy in Suellen et al. (

1998b); and the optical spectroscopy in Snellen et al. (

19992).

1999a).

This paper describes multi-frequency VLBI observations of the sample. and the radio-morphologies of the individual sources.

This paper describes multi-frequency VLBI observations of the sample, and the radio-morphologies of the individual sources.

Wha

What

the expected Hw luminosity even if T<10 Myrs.

the expected ${H\alpha}$ luminosity even if $<10$ Myrs.

From the figure we also see that stochasticity implies a large spread 1 the He luminosities for Levy<10 ss.

From the figure we also see that stochasticity implies a large spread in the $\alpha$ luminosities for $L_{FUV}<10^{39}$ $^{-1}$.

The presence of outliers in low-mass clusters populated according to a stochastic IMF implies that the relation betwee the cluster luminosity and its mass is no longer linear. or uniquely determined.

The presence of outliers in low-mass clusters populated according to a stochastic IMF implies that the relation between the cluster luminosity and its mass is no longer linear, or uniquely determined.

We show in Fig.

I] the distributio of cluster masses as a function of the cluster bolometric luminosity at birth.

\ref{mb} the distribution of cluster masses as a function of the cluster bolometric luminosity at birth.

We have simulated the mass distributio using for massive clusters a M — Lj, relation consister= with that given by the SED models for objects younger tha 3MMvr.

We have simulated the mass distribution using for massive clusters a $M$ – $L_{bol}$ relation consistent with that given by the SED models for objects younger than Myr.

The filled dots in the Fig.

11. are the average values of logM. in solar units. for different values of log Lj.

\ref{mb} are the average values of $log M$, in solar units, for different values of log $L_{bol}$.

For clusters. stochastic sampling of the IMF implies a mass higher. on average. than that obtained from the extrapolation of a fully populated IMF.

For clusters, stochastic sampling of the IMF implies a mass higher, on average, than that obtained from the extrapolation of a fully populated IMF.

Deviations from a linear scaling are evident as Lo; approaches 10“ ss! and become relevant for the average mass when Ly,<lO" eergss7!.

Deviations from a linear scaling are evident as $L_{bol}$ approaches $10^{40}$ $^{-1}$ and become relevant for the average mass when $L_{bol}\le 10^{39}$ $^{-1}$.

A cluster of given luminosity can be of smaller mass when some bright outlier dominates its integrated light. or can have a larger mass ifno outliers are present.

A cluster of given luminosity can be of smaller mass when some bright outlier dominates its integrated light, or can have a larger mass ifno outliers are present.

The dashed line in the Fig.

11. shows the linear approximation to the /ogM — /ogl,,; relation for clusters at birth.

\ref{mb} shows the linear approximation to the $log M$ – $log L_{bol}$ relation for clusters at birth.

We use this relation to derive the cluster mass from the fitted bolometric luminosity.

Given a cluster age 7. we define a critical luminosity

Given a cluster age $T$ , we define a critical luminosity

Thus we may require only around 5% of the ISM to be ejected to the IGM on an average in models with f,0.2 This is comparable with semi-analytic models of early star formation. outflows and IGM enrichment that have been studied in the literature.

Thus we may require only around $5\%$ of the ISM to be ejected to the IGM on an average in models with $f_\ast \simeq 0.2$ This is comparable with semi-analytic models of early star formation, outflows and IGM enrichment that have been studied in the literature.

We have assumed the same loss fraction for ISM for galaxies over the entire range of masses.

This. of course. is not true.

This, of course, is not true.

We expect that the low mass galaxies can potentially disperse a large fraction of the ISM in supernova explosions but larger galaxies can retain most of their ISM (Larson1974:Dekel&Silk1986)..

We expect that the low mass galaxies can potentially disperse a large fraction of the ISM in supernova explosions but larger galaxies can retain most of their ISM \citep{1974MNRAS.169..229L, 1986ApJ...303...39D}.

If most of the IGM enrichment is done by metals that form in dwarf galaxies then the constraint is not very stringent.

In most models. the fraction of mass in galaxies with a halo mass of less than 1027 AZ. is larger than 10X even at ><6.

In most models, the fraction of mass in galaxies with a halo mass of less than $10^{10}$ $M_\odot$ is larger than $10\%$ even at $z \simeq 6$.